/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.jute;

import java.io.ByteArrayOutputStream;
import java.io.IOException;

/**
 * Various utility functions for Hadoop record I/O runtime.
 */
public class Utils {

	private static final char[] hexchars = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E',
			'F' };

	/**
	 * equals function that actually compares two buffers.
	 *
	 * @param onearray First buffer
	 * @param twoarray Second buffer
	 * @return true if one and two contain exactly the same content, else false.
	 */
	public static boolean bufEquals(byte onearray[], byte twoarray[]) {
		if (onearray == twoarray)
			return true;
		boolean ret = (onearray.length == twoarray.length);
		if (!ret) {
			return ret;
		}
		for (int idx = 0; idx < onearray.length; idx++) {
			if (onearray[idx] != twoarray[idx]) {
				return false;
			}
		}
		return true;
	}

	public static int compareBytes(byte b1[], int off1, int len1, byte b2[], int off2, int len2) {
		int i;
		for (i = 0; i < len1 && i < len2; i++) {
			if (b1[off1 + i] != b2[off2 + i]) {
				return b1[off1 + i] < b2[off2 + 1] ? -1 : 1;
			}
		}
		if (len1 != len2) {
			return len1 < len2 ? -1 : 1;
		}
		return 0;
	}

	/**
	 * Converts a CSV-serialized representation of buffer to a new
	 * ByteArrayOutputStream.
	 * 
	 * @param s CSV-serialized representation of buffer
	 * @throws java.io.IOException
	 * @return Deserialized ByteArrayOutputStream
	 */
	static byte[] fromCSVBuffer(String s) throws IOException {
		if (s.charAt(0) != '#') {
			throw new IOException("Error deserializing buffer.");
		}
		ByteArrayOutputStream stream = new ByteArrayOutputStream();
		if (s.length() == 1) {
			return stream.toByteArray();
		}
		int blen = (s.length() - 1) / 2;
		byte[] barr = new byte[blen];
		for (int idx = 0; idx < blen; idx++) {
			char c1 = s.charAt(2 * idx + 1);
			char c2 = s.charAt(2 * idx + 2);
			barr[idx] = Byte.parseByte("" + c1 + c2, 16);
		}
		stream.write(barr);
		return stream.toByteArray();
	}

	/**
	 * 
	 * @param s
	 * @throws java.io.IOException
	 * @return
	 */
	static String fromCSVString(String s) throws IOException {
		if (s.charAt(0) != '\'') {
			throw new IOException("Error deserializing string.");
		}
		int len = s.length();
		StringBuilder sb = new StringBuilder(len - 1);
		for (int i = 1; i < len; i++) {
			char c = s.charAt(i);
			if (c == '%') {
				char ch1 = s.charAt(i + 1);
				char ch2 = s.charAt(i + 2);
				i += 2;
				if (ch1 == '0' && ch2 == '0') {
					sb.append('\0');
				} else if (ch1 == '0' && ch2 == 'A') {
					sb.append('\n');
				} else if (ch1 == '0' && ch2 == 'D') {
					sb.append('\r');
				} else if (ch1 == '2' && ch2 == 'C') {
					sb.append(',');
				} else if (ch1 == '7' && ch2 == 'D') {
					sb.append('}');
				} else if (ch1 == '2' && ch2 == '5') {
					sb.append('%');
				} else {
					throw new IOException("Error deserializing string.");
				}
			} else {
				sb.append(c);
			}
		}
		return sb.toString();
	}

	/**
	 * 
	 * @param s
	 * @throws java.io.IOException
	 * @return
	 */
	static byte[] fromXMLBuffer(String s) throws IOException {
		ByteArrayOutputStream stream = new ByteArrayOutputStream();
		if (s.length() == 0) {
			return stream.toByteArray();
		}
		int blen = s.length() / 2;
		byte[] barr = new byte[blen];
		for (int idx = 0; idx < blen; idx++) {
			char c1 = s.charAt(2 * idx);
			char c2 = s.charAt(2 * idx + 1);
			barr[idx] = Byte.parseByte("" + c1 + c2, 16);
		}
		stream.write(barr);
		return stream.toByteArray();
	}

	/**
	 * 
	 * @param s
	 * @return
	 */
	static String fromXMLString(String s) {
		StringBuilder sb = new StringBuilder();
		for (int idx = 0; idx < s.length();) {
			char ch = s.charAt(idx++);
			if (ch == '%') {
				char ch1 = s.charAt(idx++);
				char ch2 = s.charAt(idx++);
				char res = (char) (h2c(ch1) * 16 + h2c(ch2));
				sb.append(res);
			} else {
				sb.append(ch);
			}
		}

		return sb.toString();
	}

	static private int h2c(char ch) {
		if (ch >= '0' && ch <= '9') {
			return ch - '0';
		} else if (ch >= 'A' && ch <= 'F') {
			return ch - 'A';
		} else if (ch >= 'a' && ch <= 'f') {
			return ch - 'a';
		}
		return 0;
	}

	/**
	 * 
	 * @param buf
	 * @return
	 */
	static String toCSVBuffer(byte barr[]) {
		if (barr == null || barr.length == 0) {
			return "";
		}
		StringBuilder sb = new StringBuilder(barr.length + 1);
		sb.append('#');
		for (int idx = 0; idx < barr.length; idx++) {
			sb.append(Integer.toHexString(barr[idx]));
		}
		return sb.toString();
	}

	/**
	 * 
	 * @param s
	 * @return
	 */
	static String toCSVString(String s) {
		if (s == null)
			return "";

		StringBuilder sb = new StringBuilder(s.length() + 1);
		sb.append('\'');
		int len = s.length();
		for (int i = 0; i < len; i++) {
			char c = s.charAt(i);
			switch (c) {
			case '\0':
				sb.append("%00");
				break;
			case '\n':
				sb.append("%0A");
				break;
			case '\r':
				sb.append("%0D");
				break;
			case ',':
				sb.append("%2C");
				break;
			case '}':
				sb.append("%7D");
				break;
			case '%':
				sb.append("%25");
				break;
			default:
				sb.append(c);
			}
		}
		return sb.toString();
	}

	/**
	 * 
	 * @param s
	 * @return
	 */
	static String toXMLBuffer(byte barr[]) {
		if (barr == null || barr.length == 0) {
			return "";
		}
		StringBuilder sb = new StringBuilder(2 * barr.length);
		for (int idx = 0; idx < barr.length; idx++) {
			sb.append(Integer.toHexString(barr[idx]));
		}
		return sb.toString();
	}

	/**
	 * 
	 * @param s
	 * @return
	 */
	static String toXMLString(String s) {
		if (s == null)
			return "";

		StringBuilder sb = new StringBuilder();
		for (int idx = 0; idx < s.length(); idx++) {
			char ch = s.charAt(idx);
			if (ch == '<') {
				sb.append("&lt;");
			} else if (ch == '&') {
				sb.append("&amp;");
			} else if (ch == '%') {
				sb.append("%25");
			} else if (ch < 0x20) {
				sb.append("%");
				sb.append(hexchars[ch / 16]);
				sb.append(hexchars[ch % 16]);
			} else {
				sb.append(ch);
			}
		}
		return sb.toString();
	}

	/** Cannot create a new instance of Utils */
	private Utils() {
		super();
	}
}
